Stimulating growth and xylindein production of Chlorociboria aeruginascens in agar-based systems

The Chlorociboria genus is widely distributed throughout the world; Chlorociboria aeruginascens (Nyl.) Kanouse and Chlorociboria aeruginosa (Oeder) Seaver are native to North America (Ramamurthi et al. 1957). Xylindein, the penetrating blue-green pigment produced by C. aeruginascens, (Mizuki et al. 2003), can be readily found in forests on decaying wood, especially Populus sp. (Blanchette et al. 1992) and Quercus sp. (Dennis 1956).Particular interest has been devoted to xylindein due to its vibrant color. The composition of this pigment has been well studied (Saikawa et al. 2000), and some research has looked at possible uses outside of the decorative market (Kunimitsu et al. 2005). Traditionally, wood stained by Chlorociboria sp. has been used for Intarsia inlay and other artistic media (Blanchette et al. 1992; Otterstedt 2001). Xylindein is of particular interest within the field of value-added wood products, as spalted wood can be sold at a price premium (Donovan et al. 2003), increasing the revenue of forested lands and low-value timber.Although numerous fungus species have been researched for decorative wood staining (Robinson SC: Developing fungal pigments for 'painting' vascular plants. Appl Microbiol Biotechnol 2012), development of Chlorociboria sp. staining under controlled conditions has encountered several large hurdles. The native North American Chlorociboria sp. appear to preferentially grow on heavily decayed wood (Johnston & Park 2005), and grow very slowly both on prepared laboratory media, and in mono and dual culture jar systems (Robinson & Laks 2010a). Chlorociboria sp. also appears to preferentially stain some wood species over others, with Populus sp. and Acer saccharum Marsh. showing significantly more xylindein staining than Betula sp. or Tilia americana L. (Robinson & Laks 2010a).When inducing fungal pigmentation in wood under controlled conditions, the rate of culture growth in the initial media plates is often the limiting factor. If fungi